Volcanoes are fiery mountains formed when magma from deep inside the Earth erupts through openings in the crust, called vents. They come in various types, like stratovolcanoes and shield volcanoes, each with unique shapes and eruption patterns. Found globally but concentrated in places like the Pacific Ring of Fire, volcanoes can be active, erupting regularly, or dormant for long periods. While they create new landforms and fertile soils, volcanic eruptions also pose risks such as lava flows, ash clouds, and pyroclastic flows, necessitating careful monitoring to understand their behavior and protect nearby communities.